[Dirtmod15jr]

Ok Guys I know I have been asking a lot of weird questions but here is one that is different. I am looking at running smaller tires than stock. With the type of racing I am doing I need tires that resemble flat track tires. Hoosier or American racer do not make them in 12" I have seen the Duro tires but most I have seen are 6 ply and that is to stiff of a sidewall. I did find some tires that are 23 X 10- 12 and are 4ply. They have a descent tread and less side knob. My question is will running these tires harm the diff's or trans since they are shorter and all 4 are the same size width wise? I wont likely run in AWD but just not sure about it?

 

[mark5193]

if anything, it would be easier on everything! you will notice a gear change though, top speed will be reduced. acceleration will be better!

 

[Dirtmod15jr]

if anything, it would be easier on everything! you will notice a gear change though, top speed will be reduced. acceleration will be better!

That is exactly what I thought and hoped for. The longest straight is probably
50 yards tops. Getting off the corners better is the key. And the benefit of being able to stay on the gas longer without worrying about tires digging in and rolling will make a big difference.

I am just not sure about the diffs being hurt? I don"t see how but you never know.

Thanks Man

 

[mark5193]

you may have to change clutching a little too? you would probably hit the rev limiter real easy!

 

[Dirtmod15jr]

you may have to change clutching a little too? you would probably hit the rev limiter real easy!

Man I didn't even think about the limiter. That may be an issue. I have stock programming and no way to change that before tomorrow. You think the difference between 25 X10 -12 and 23X10-12 would make enough diff to max out before the end of the straight. I think the fastest we go down the straight is 40.

 

[mark5193]

won't make a difference down the straight, mainly when you first hammer it coming out of the corner, the lower gearing will rev quicker, spin the tires easier, hitting the limiter even quicker. don't worry about hitting the rev limiter, it is there for a reason. try it and see? maybe bring 2 sets of tires?

 

[Dirtmod15jr]

won't make a difference down the straight, mainly when you first hammer it coming out of the corner, the lower gearing will rev quicker, spin the tires easier, hitting the limiter even quicker. don't worry about hitting the rev limiter, it is there for a reason. try it and see? maybe bring 2 sets of tires?

I keep it gassed up in the corners but the rpm's do go down. Getting it to come back up quicker will help keep the speed up coming off. I thought about a clutch kit but going with tires kills two birds with one stone.

I have the knobbys I have been running going with me. The flat track tires are mounted on steel OEM back wheels all the way around. so they are wider in the front than normal. I have wheel spacers so the rims don't drag the a frames.

 

[cmcdaniel]

You should consider Maxxis Razr 4-speeds, guys use those in Closed Course Racing and I have used them and they are amazing tires. They do wear pretty quick if you drive on the street at all. I would be willing to bet they would work really well for what you are doing...

Running smaller tires you will aquire miles alot more quickly, not good for resale...

 

[Dirtmod15jr]

You should consider Maxxis Razr 4-speeds, guys use those in Closed Course Racing and I have used them and they are amazing tires. They do wear pretty quick if you drive on the street at all. I would be willing to bet they would work really well for what you are doing...

Running smaller tires you will aquire miles alot more quickly, not good for resale...

I did look at those tires and they look great. But as fast as we wear tires I am afraid I would be buying a right rear everynight.

I didn't think of the mileage issue either. Oh well by the time I am done with this thing no one would want it. LOL

Thanks

 

[Johnpeq]

Brian, those 6plys may have a lower ply in the sidewall,
John

 

[Dirtmod15jr]

Brian, those 6plys may have a lower ply in the sidewall,
John

John

I did see one of the Duro's on a quad and it was pretty stiff in the sidewall. I have the new ones mounted and ready to go. I didn't get to test them tonight but first thing in the morning I will have it out. I am taking my tire grinder with me in case they glaze a little. But I think they should work cool on there.

 

[MotoXXX]

I'm thinking your clutching will change a lot. Someone in an earlier post said the rev limiter is there for a reason, but.....DO NOT lay on the rev limiter, it is hard on the clutches, not to mention other things. You really need either adjustable fly weights or two different sets of weights for different tires.

 

[Tuf-Skin]

don't worry about hitting the rev limiter, it is there for a reason.

actually you do want to worry about constantly hitting the rev limiter.
the soft limiter retards the timing and pulls fuel making it run lean and hot.

adjust the clutch so that you are just below the soft limiter.

 

[Dirtmod15jr]

I'm thinking your clutching will change a lot. Someone in an earlier post said the rev limiter is there for a reason, but.....DO NOT lay on the rev limiter, it is hard on the clutches, not to mention other things. You really need either adjustable fly weights or two different sets of weights for different tires.

Yeah these new tires are a good 3 to 4 inches shorter than stock. I agree that I may need to clutch it. I just have to figure out what weights to use. I will know more tomorrow night. I can always put my stock tires back on after practice.

 

[Dirtmod15jr]

don't worry about hitting the rev limiter, it is there for a reason.

actually you do want to worry about constantly hitting the rev limiter.
the soft limiter retards the timing and pulls fuel making it run lean and hot.

adjust the clutch so that you are just below the soft limiter.

I just got off the phone with a buddy of mine who has another ECM that moves the rev limiter out further. He is taking it with us so I can try it too.

 

[MotoXXX]

don't worry about hitting the rev limiter, it is there for a reason.

actually you do want to worry about constantly hitting the rev limiter.
the soft limiter retards the timing and pulls fuel making it run lean and hot.

adjust the clutch so that you are just below the soft limiter.

I just got off the phone with a buddy of mine who has another ECM that moves the rev limiter out further. He is taking it with us so I can try it too.

If you go to 7000 rpm you're playing with fire with the stock crank....you'll eventually twist it or at the least bend it!

 

[Dirtmod15jr]

actually you do want to worry about constantly hitting the rev limiter.
the soft limiter retards the timing and pulls fuel making it run lean and hot.

adjust the clutch so that you are just below the soft limiter.

I just got off the phone with a buddy of mine who has another ECM that moves the rev limiter out further. He is taking it with us so I can try it too.

If you go to 7000 rpm you're playing with fire with the stock crank....you'll eventually twist it or at the least bend it!

Man I doubt I will make it to anywhere near 7000. Its rained 2 days here and now its cool out. The wind has blown some but the ground is nice. I see the track being very tacky and staying that way all night.If I hit 6500 I would be surprised. 50yards is probably all the longer the front straight is. Its when the track dries up and the wheels are spinning is when I am afraid I might run into trouble. But I can foot the gas to keep that to a minimum.

 

[MotoXXX]

Sounds like fun, just watch the tach!

 

[Dirtmod15jr]

Sounds like fun, just watch the tach!

Its a blast and not really that hard on the machine. I drive it harder in the woods. Results so far.

1st night Fastest Qualifier, won 1st heat, won feature
2nd night Fastest qualifier, Blew the belt to smithereens.
3rd night Its on!!!!!!

 

[MotoXXX]

Sounds like fun, just watch the tach!

Its a blast and not really that hard on the machine. I drive it harder in the woods. Results so far.

1st night Fastest Qualifier, won 1st heat, won feature
2nd night Fastest qualifier, Blew the belt to smithereens.
3rd night Its on!!!!!!

Good luck!...Go get another win!